PCNA and Familial prostate cancer: For the prostate cancer donors (at baseline) the gene expression was as follows: SESN1 (80%) > CDKN1A (60%) > FDXR (40%) > PCNA (40%) indicating that all genes in the 4-gene signature were related to G2 radiosensitivity, however statistical significance was not found in a correlation analysis of G2 scores with each gene.